1. Field of the Invention
This invention relates to an escalator apparatus which can transport cars, for instance prams or wheelchairs for physically handicapped persons and the like, in addition to ordinary passengers.
In particular, it relates to an escalator apparatus having a construction which guarantees a tread depth dimension which is effective for loading the cars by maintaining at least two upper and lower steps at the same level.
2. Description of the Prior Art
Usually, in an ordinary escalator apparatus, since the depth dimension of each step is short, cars, for instance wheelchairs for disabled persons, cannot be safely transported by loading them in a level attitude. Because of this, steps of the escalator apparatus have recently been proposed which will maintain at least two upper and lower steps, out of the multiple steps which are arranged in an endless state, at the same height and can thus guarantee a car loading space with a deep depth.
For instance, the escalator apparatus described above is disclosed by Japanese Patent Publication No. 63-19437.
A proposed construction of this escalator apparatus is briefly described with reference to FIGS. 10 through 12.
First, as shown in FIG. 10, main frame 1 of the escalator apparatus is provided to span in an inclined state between upper and lower floors. A circuit composed of outward path 2 on the top side, return path 3 on the under side and reversing sections 4 and 5 at the upper and lower floor ends is constructed by arranging guide rails and step sprockets between upper and lower floor stepping on and off points 6 and 7 of main frame 1. This circuit is provided with multiple steps 8 arranged so that they can run and be driven in an endless state. Each step 8 has a respective tread 9 on its upper side and, at the same time, respective left and right pairs of front and rear wheels 10a and 10b underneath.
Out of these multiple steps 8, two upper and lower specialized steps 8A and 8B which are adjacent to each other are suitably specified for loading a wheelchair K. Out of these upper and lower two steps, as shown in FIGS. 11 and 12, the lower first specialized step 8A has a construction divided into a step main body 11, supported by front and rear wheels 10a and 10b, and moveable tread 12, which is housed so that it is capable of rising and falling relative to the step main body 11. On the other hand, the adjacent upper step, second specialized step 8B, has the same construction as an ordinary step 8, but has lift mechanism 13 constructed inside it.
This lift mechanism 13 has a construction provided with pairs of pinions 14 which rotate when energised from the main frame 1, racks 15 which engage with the pinions 14, and arms 16 which extend to the rear from the racks 15 on the left and right sides respectively.
Usually, as shown in FIG. 12, the left and right arms 16 of the lift mechanism 13 are withdrawn inside the second specialized step 8B and have no connection with the first specialized step 8A. Thus, all of steps 8, 8A and 8B move in the same way as ordinary escalator steps to transport general passengers.
Also, in the case of loading the wheelchair K on the first and second steps 8A and 8B, all of the steps are paused at the level section 2a of the outward path 2, and from the state shown in FIG. 12, the pinions 14 of the lift mechanism 13 are energised to rotate by the energising unit (not shown) from the main frame 1. The left and right arms 16 operate to project in the rear direction together with the racks 15 which are engaged, and support the moveable tread 12 of the first specialized step 8A from underneath. In this state, as it moves from the level section 2a to the inclined section 2b of the outward path 2, the moveable tread 12 of the first specialized step 8A is caused to rise relative to the step main body 11 by the support of the left and right arms 16. As shown in FIG. 11, it is maintained at the same height as the second specialized step 8B. Thus, a satisfactory loading space for wheelchairs is guaranteed. That is to say, the design is to guarantee a deeper tread depth dimension which is effective for wheelchair loading.
Also, another specialized step 8C, which becomes in a rear-tilted state only when in the wheelchair mode, is provided adjacent to the upper side of the second specialized step 8B to take account of the case when a satisfactory wheelchair loading space cannot be guaranteed by the first and second specialized steps 8A and 8B alone, that is to say to take account of the case when a foot-rest or the like is provided and projects in front of the wheelchair K.
In the prior art escalator apparatus such as that described above, the moveable tread 12 of the first specialized step 8A is supported by the lift mechanism 13 so that it is maintained at the same height as the second specialized step 8B. Therefore, a satisfactory loading space for the wheelchair K can be simply guaranteed. However, since the moveable tread 12 rises and is supported one-sidedly by the left and right arms 16 of the lift mechanism 13, the arms 16 may bend or tilt downward under the weight of the moveable tread 12 itself and the load of the wheelchair K and its user loaded on them. Therefore, the trailing edge of the moveable tread 12 may tilt rearward so that its trailing edge becomes lower than its leading edge. As a result, there is the problem of a great risk that the wheelchair K loaded on the moveable tread 12 may be subject to a shifting force in the downward direction and roll downwards.
In addition, in the prior art escalator apparatus such as that described above, when the movable tread 12 of the first specialized step 8A is maintained at the same height as the second specialized step 8B, and the wheelchair K is loaded on the moveable tread 12, all of the steps are made to pause.
Accordingly it has a problem in its ability to transport cars and passengers by the escalator apparatus.